hi mikko,
you do not want to change the baudrate going to the bluetooth module
unless you have a really good reason.
ben has a good question: are you having these problems with just one node?
since we know that boilerplate works well left as is, if you only have
one node running, try to change just one thing at a time until it breaks...
-steve
On 07/24/2012 11:11 AM, Benjamin Kuris wrote:
What sample rate and how many channels?
How many devices in your piconet?
Any other RF in 2.4GHz band?
Are you using stock boilerplate data packets or are you sending full
ACL packets (~128bytes data) to minimize BT overhead?
Typically you don't need to mess with the baudrate but minimizing BT
overhead will improve results if you can accept a little bit of
latency.
I'm sure others will chime in.
-Ben
On Tue, Jul 24, 2012 at 10:57 AM, Mikko Rasa <[email protected]> wrote:
I'm trying to use a Shimmer 9DoF sensor with the boilerplate firmware, but
bluetooth transmission is giving me a hard time. It's dropping a lot of
bytes, making data streaming unreliable and certain commands unusable. In
particular, I can't get an intact reply from the inquiry command to discover
the order of channels being sent, so I have to hardcode this into my program
based on the boilerplate sources. With the data packets I could use the
packet identifier to synchronize the stream and throw out any truncated
packets; this might spuriously reject good packets if they contain embedded
zero bytes, but I estimate I could recover around 80% of the packets this
way.
Is there anything I could do to improve the reliability? I've already tried
different sampling rates, as well as messing with the baud rate used between
the MSP430 and the BT module. Neither of these seems to have any effect on
the reliability, unless I change the baud rate so far out of spec that all
transmissions stops.
--
Mikko
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